White-tipped gill

I got my first axie at a few weeks old back in mid July. In August I noticed this white spot on the tip of his one gill (left middle).. immediately did tea baths and everything the forums said for potential fungi.. but the spot never goes away? It also never grows. It's not fuzzy or anything, and it never changes. It has been months, now. His water parameters have stayed almost perfect with the exception of the occasional trace ammonia issue (I read this can be from sand.) It's stressing me out because I have no idea what it could be.. doesn't seem like growth because none of his other gills did this and the affected one hasn't grown. I know that his gills also seem a bit small.. but his tank is HOOKED up and he's really spoiled w good oxygen.. recently purchased a 30 gal to transition him into once it's fully cycled to see if that helps..

Also, does he seem fat enough? I'm worried he's malnourished. I feed him freeze dried brine shrimp and blood worms, and am trying to transition him into some like carnivore pellets. I make sure the protein in whatever he is eating is over 45% and feed him as much as he'll eat twice a day. He eats well and is very active! Any tips? Thank you!!

He is too skinny. Try feeding him nightcrawlers. Maybe cut in half.

I would worry less about the white and focus on getting him fattened up. He is VERY skinny.

It’s fungus, tub with 100% daily water changes and it should clear up. Also feed night crawlers as suggested above!